ASASSN-25eq: new WZ Sge-type dwarf nova, likely a period bouncer
ASASSN discovered ASASSN-25eq on 2025-11-13.18 UT at 15.07 mag. Then
it brightened to g=14.0 mag on 2025-11-15. The VSX lists g=21.9 mag as
the counterpart, hence the outburst amplitude is ~8 mag.
https://vsx.aavso.org/index.php?view=detail.top&oid=10868208https://asas-sn.osu.edu/sky-patrol/coordinate/579ca10e-176d-4c3b-958f-03a39…
Josch Hambsh and Berto Monard have reported the time-resolved
observations of ASASSN-25eq. The light curve shows a 1-mag dip around
2025-11-25 UT. After this dip, clear superhumps are present, with a
period of ~0.0645 d. There is no clear modulation before the dip.
Thus, ASASSN-25eq is a new WZ Sge-type dwarf nova, with a
double-superoutburst feature often observed in a period bouncer
system.
See e.g. https://ui.adsabs.harvard.edu/abs/2018PASJ...70...47K/abstract
Given the absence of clear early superhumps, ASASSN-25eq is presumably
a face-on system. A spectrum taken with the Mookodi/Lesedi telescope
on 16 Nov. is dominated by Balmer absorption lines, which supports
this interpretation.
Time-resolved observations are encouraged.
Best regards,
Yusuke
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South African Astronomical Observatory, Postdoc fellow
Yusuke TAMPO / 反保 雄介
EMAIL: tampo(a)kusastro.kyoto-u.ac.jp
ALT. EMAIL: yusuke(a)saao.ac.za
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TCP J07454958-2442056: most likely a WZ Sge-type dwarf nova
TCP J07454958-2442056 was discovered by Yuji Nakamura on 13th Oct 2025
at 14.0 mag (unfiltered). According to VSX, the outburst amplitude is
~8.2 mag.
https://vsx.aavso.org/index.php?view=detail.top&oid=10868099
Josch Hambsch and Sjoerd Dufoer have reported the time-resolved
observations of this source. The light curve shows possible superhumps
with a period of ~0.055 d, although I cannot conclude due to its
faintness and 1-d aliases. Given its large outburst amplitude, almost
40-d outburst duration, and short superhump period, TCP
J07454958-2442056 is most likely a new WZ Sge-type dwarf nova.
Note that the system has already faded below the detection level of ATLAS.
https://fallingstar-data.com/forcedphot/queue/3502597/
Best regards,
Yusuke
--
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South African Astronomical Observatory, Postdoc fellow
Yusuke TAMPO / 反保 雄介
EMAIL: tampo(a)kusastro.kyoto-u.ac.jp
ALT. EMAIL: yusuke(a)saao.ac.za
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ASASSN-25en: new SU UMa-type dwarf nova
ASASSN discovered ASASSN-25en on 2025-11-03 UT at 14.94 mag. The
outburst amplitude in the VSX is ~7.5 mag.
https://vsx.aavso.org/index.php?view=detail.top&oid=10868163
Josch Hambsch and Itoh-san have reported the time-resolved
observations. The light curve after 2025-11-11 UT shows a
single-peaked superhump with a period of either 0.06003(3) or
0.06390(3) d. Thus, ASASSN-25en is a new SU UMa-type dwarf nova. The
rapid decline from the outburst was observed around 2025-11-21 UT.
Best regards,
Yusuke
--
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South African Astronomical Observatory, Postdoc fellow
Yusuke TAMPO / 反保 雄介
EMAIL: tampo(a)kusastro.kyoto-u.ac.jp
ALT. EMAIL: yusuke(a)saao.ac.za
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Dear colleagues,
TCP J06364062+3318310 was discovered by K. Sokolovsky et al. (NMW Survey) on
2025 Nov 17.99 at mag 13.6CV. The quiescent counterpart is a 21.3 r mag
star, implying an outburst amplitude of ~8 mag.
I have just completed the analysis of my unfiltered CCD time-series
observations of TCP J06364062+3318310, obtained on 2025 Nov 25/26 at CBA
Extremadura Observatory. The data were acquired under clear skies with a
0.40-m f/5.1 telescope and a Moravian G2-4000 CCD camera.
I also obtained observations on several nights prior to Nov 25/26, but those
did not reveal any obvious modulation. In contrast, the Nov 25/26 light
curve clearly shows regular superhump modulations with an amplitude of 0.30
mag. A period analysis using ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle
and PDM methods (Peranso 3.1) yields a combined superhump period of 0.0661
+/- 0.0008d. The object was measured at mag CV = 15.3 on Nov 26th.
Image calibration and photometry were carried out using the latest release
of Phoranso, which enabled simultaneous photometry of several additional
variable stars in the same field of view.
These results establish TCP J06364062+3318310 as a new SU UMa-type dwarf
nova. Further follow-up observations are strongly encouraged to refine the
superhump period and study its evolution.
I will submit my observations to AAVSO, CBA and VSNET for further analysis.
With kind regards,
Tonny
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Tonny Vanmunster
CBA Belgium Observatory
CBA Extremadura Observatory
http://www.cbabelgium.co <http://www.cbabelgium.com/> m
PERANSO : The Light Curve and Period Analysis Software
http://www.peranso.co <http://www.peranso.com/> m
PHORANSO: Photometric Reduction and Analysis Software
http://www.phoranso.com <http://www.phoranso.com/>